Throttle lever system for a fluid-activated, percussive paving breaker

Abstract

A throttle lever for a paving breaker having rear housing bore. A valve assembly housing plug is removably inserted into the bore. A backhead plate retains the valve assembly housing plug in the bore. An elongated throttle lever has a first end pivotally trapped between the backhead plate and the valve assembly housing plug. A second end of the throttle lever extends above the backhead plate, and forms an operator contact surface. An intermediate portion between the first end and second end of the throttle lever operably contacts a fluid inlet valve.

Having described the invention, what is claimed is: 
     
       1. A paving breaker having a rear housing bore, with a valve assembly retained therein, the paving breaker having an inlet port therein for high pressure fluid, the inlet port having therein an elastically biased, normally closed inlet valve, the paving breaker having a throttle lever system comprising: (a) a valve assembly housing plug, removably inserted into said rear housing bore;   (b) a backhead plate removably connected to said rear housing, to retain said valve assembly housing plug in said rear housing bore;   (c) means for fluid tight sealing of said valve assembly housing plug in said rear housing bore;   (d) a throttle lever comprising: (i) an elongated body member having a first portion terminating in a first end; a second portion terminating in a second end, and means on said body for contacting said inlet valve;   (ii) said first portion extending between said backhead plate and a top surface of said valve assembly housing plug;   (iii) said first end pivotably mounted between said backhead plate and said top surface of said valve assembly housing plug; and   (iv) said second portion extending above said backhead plate;     (e) said inlet valve being elastically normally biased to contact said throttle lever; and   (f) whereby said throttle lever pivots about said first end in a first direction, in response to operator pressure on said second portion and in a second direction in response to said biased inlet valve.   
     
     
       2. The throttle lever of claim 1 wherein said first end is shaped into a curved pivot surface, said curved pivot surface being trapped in a pocket formed in said valve assembly housing plug. 
     
     
       3. The throttle lever of claim 2 wherein said first portion is pivotable about said first end. 
     
     
       4. The throttle lever of claim 3 wherein said first and second portions, viewed in elevation, are substantially parallel to, and offset from, each other, and an intermediate portion extends diagonally therebetween. 
     
     
       5. The throttle lever of claim 4 wherein said second portion forms an operator hand contact surface. 
     
     
       6. A paving breaker having a rear housing bore, with a valve assembly retained therein, the paving breaker having an inlet port therein for high pressure fluid, the inlet port having therein an elastically biased, normally closed inlet valve, the paving breaker having a throttle lever system comprising: (a) a valve assembly housing plug removably inserted into said rear housing bore;   (b) a backhead plate removably connected to said rear housing, to retain said valve assembly housing plug in said rear housing bore;   (c) means for fluid tight sealing of said valve assembly housing plug in said rear housing bore;   (d) said throttle lever comprising: (i) an elongated body member having a first portion terminating in a pivot end having a curved pivot surface; a second portion terminating in an operator's hand contact surface, and an intermediate portion between said first and second portions, for contacting said inlet valve;   (ii) said pivot surface pivotally trapped in a pocket formed in a top surface of said valve assembly housing plug;   (iii) said first portion extending between said backhead plate and said top surface of said valve assembly housing plug and pivotally trapped in a pivot pocket formed in said top surface of said valve assembly housing plug; and   (iv) said second portion extending above said backhead plate;     (e) said inlet valve being elastically normally biased to contact said throttle lever intermediate portion; and   (f) whereby said throttle lever pivots about said pivot end in a first direction, in response to operator pressure on said hand contact surface and in a second direction in response to said biased inlet valve.